LGBT advocates and the father of the boy for whom a Michigan anti-bullying law is named are slamming the state senate, claiming a last-minute First Amendment tweak gives "a major green light" to school bullies.

The Michigan Senate this week passed a bill to authorize the law, Matt's Safe School Law, which is named after Matt Epling, a freshman from East Lansing, Mich., who killed himself after being bullied by upperclassmen in 2002.

But in a change before Wednesday's vote, Republican lawmakers added a clause ensuring that the bill "does not prohibit a statement of a sincerely held belief or moral conviction" of a student or school worker.

"They kind of snuck in this extra paragraph, really kind of setting apart kids that feel their religious beliefs, their moral convictions, basically, can allow them to bully," said Matt Epling's father, Kevin Epling. "That one paragraph, though, negates most of the things that we tried to put in."

Michigan is one of three U.S. states without an anti-bullying law.

Kevin Epling told ABC News today that the change was made after he'd spent more than six years pushing for the legislation.

Today, he called the law as it stands "a time bomb," adding that the change created a loophole that allowed students to use their religion to justify bullying another.

"I think it fails the memory of Matt," he said. "We cannot go backward and say, in any way, shape or form, in a piece of legislation that it is OK under religious grounds to harass or harm your fellow student. And that's what they've done."

Protecting the First Amendment

Republican state Sen. Rick Jones, the bill's sponsor, told ABC News today that the GOP wanted to make sure students' First Amendment rights were protected.

"There were some caucus members who worried that if a child stood up in sex education class or speech class and made a statement: 'In my religion, I don't believe in gay marriage,' or something, they didn't want the child to be evicted from school for just making a statement," he said.

The state lawmaker said the bill was personal to him because his son, now 31, had been a victim of bullying, and because a friend's granddaughter had fatally shot herself after being bullied.

"Nothing in the bill is intended that the child could confront another child and abuse them in any way," Jones told ABC News today. "I wouldn't have a problem with some of the language being removed as long as it was very clear that a student's First Amendment rights were protected. ... There is no intent on my part to justify bullying, in any form."

Dan Savage, a sex columnist who launched the It Gets Better Project to encourage gay youth, however, called the bill in its current form "a license to bully."

"I was appalled when I read that it had passed. ... It really is a God-hates-fags-special-rights-for-Christians-to-abuse-LBGT-kids-in-the-school law," he told ABC News today.

"It's a law that specifically empowers students, teachers, administrators [and] principals to bully LGBT kids if they can point to a moral justification," he said. "You have a right to your own religious beliefs. You don't have a right to inflict your private moral judgments on those people in a place where you are a public servant and an employee of the state. ... Michigan should be ashamed of itself."

Kevin Epling said that the anti-bullying proposal had dashed the hopes of many students who'd believed the measure would effect change in schools and protect victims.

"We need to get students to tolerate each other," he said. "We need to have more acceptance in our schools. This legislation is actually going to put another problem in the schools that does not need to be there."